Multistage infrared suppression exhaust system

Patent metadata

Field	Value
Publication number	US-11608189-B2
Application number	US-202016990688-A
Country	US
Kind code	B2
Filing date	Aug 11, 2020
Priority date	Aug 11, 2020
Publication date	Mar 21, 2023
Grant date	Mar 21, 2023

Abstract

One embodiment includes a multistage infrared suppression exhaust system for an aircraft, including: a stage one including a first exhaust conduit to receive a first exhaust air flow at a first temperature-pressure product T1P1, a second exhaust conduit to receive a second exhaust air flow at a second temperature-pressure product T2P2, and a flow integrator mechanically configured to mix the first exhaust air flow with the second exhaust air flow in an integration chamber while preventing back flow into the second exhaust conduit; and a stage two including a stage two cooling airflow to cool the mixed first and second exhaust air flows.

First claim

What is claimed is:

1. A multistage infrared suppression exhaust system for an aircraft, comprising:
a stage one comprising a first exhaust conduit extending along a first direction to receive a first engine exhaust air flow from a first engine at a first temperature-pressure product T1P1, a second exhaust conduit to receive a second engine exhaust air flow from a second engine at a second temperature-pressure product T2P2, and a flow integrator; and
wherein the first exhaust conduit terminates in a mixing chamber;
wherein the second exhaust conduit is disposed in the first engine exhaust air flow within the first exhaust conduit, the second exhaust conduit extending along a second direction perpendicular to the first direction of the first exhaust conduit, wherein the second exhaust conduit is defined by an elliptical cylindrical enclosure, with a plurality of integrator ports formed through the enclosure; and
wherein the flow integrator comprises a plurality of angled chutes disposed to direct the second exhaust air flow from the plurality of integrator ports into the mixing chamber to form a mixed airflow comprising the first and second exhaust air flows, the angled chutes being oblique relative to the first direction of the first exhaust conduit; and
a stage two comprising a stage two cooling airflow to cool the mixed first and second exhaust air flows.

2. The multistage infrared suppression exhaust system of claim 1 , wherein T1P1 is at least two times T2P2.

3. The multistage infrared suppression exhaust system of claim 1 , wherein the angled chutes of the flow integrator comprises an array of vented scissor structures.

4. The multistage infrared suppression exhaust system of claim 3 , wherein the array of vented scissor structures comprises vented scissor structures that are discretely vented such that each integrator port communicates with a respective scissor structure.

5. The multistage infrared suppression exhaust system of claim 3 , wherein the array of vented scissor structures comprises vented scissor structures that are multi-ported.

6. The multistage infrared suppression exhaust system of claim 1 , wherein the first exhaust conduit is mechanically adapted to couple to the first engine, which is a primary engine of the aircraft.

7. The multistage infrared suppression exhaust system of claim 6 , wherein the second exhaust conduit is mechanically adapted to couple to the second engine, which is a secondary engine of the aircraft.

8. The multistage infrared suppression exhaust system of claim 1 , further comprising a first stage outer encasement that circumscribes the first exhaust conduit with an air gap, the first stage outer encasement mechanically adapted to receive an insulating airflow, the insulating airflow having a temperature substantially less than T1.

9. The multistage infrared suppression exhaust system of claim 8 , wherein the insulating airflow comprises engine bay airflow.

10. The multistage infrared suppression exhaust system of claim 8 , wherein the stage two cooling airflow comprises the insulating airflow.

11. The multistage infrared suppression exhaust system of claim 1 , wherein the stage two cooling airflow comprises at least one of a primary engine bay airflow or a secondary engine bay airflow of the first engine and the second engine, respectively.

12. The multistage infrared suppression exhaust system of claim 1 , further comprising a stage three to cool air output at stage two with an ambient airflow.

13. A rotary aircraft, comprising:
an airframe;
a rotor;
a primary engine bay comprising a primary engine to drive the rotor;
a secondary power unit (SPU) bay comprising an SPU; and
an exhaust system coupled to receive a primary engine exhaust and an SPU exhaust, comprising:
a first exhaust inlet of a first exhaust conduit extending along a first direction, to receive the primary engine exhaust from the primary engine bay at a first temperature and pressure, wherein the first exhaust conduit terminates in a mixing chamber,
a second exhaust inlet of a second exhaust conduit to receive the SPU exhaust from the SPU bay at a second temperature and pressure, wherein the second exhaust conduit is defined by an elliptical cylindrical enclosure disposed within the primary engine exhaust within the first exhaust conduit, the second exhaust conduit extending along a second direction perpendicular to the first direction of the first exhaust conduit, and a plurality of integrator ports being formed through the enclosure, and
an exhaust integrator, wherein the exhaust integrator comprises a plurality of angled chutes disposed to direct the SPU exhaust from the plurality of integrator ports into the mixing chamber to form an integrated exhaust comprising the primary engine exhaust and the SPU exhaust, the angled chutes being oblique relative to the first direction of the first exhaust conduit.

14. The rotary aircraft of claim 13 , further comprising hot and cold baffles, the cold baffle disposed to receive the integrated exhaust indirectly, and the hot baffle disposed to impede the integrated exhaust from striking the cold baffle, directly.

15. The rotary aircraft of claim 13 , wherein the exhaust system is located on a port side of the airframe.

16. The rotary aircraft of claim 13 , wherein the exhaust system is located on a starboard side of the rotary aircraft.

17. The rotary aircraft of claim 13 , wherein the primary engine exhaust has a mechanical vector different from a mechanical vector of the SPU exhaust.

18. A multi-stage exhaust cooling system, comprising:
a first exhaust inlet of a first exhaust conduit extending along a first direction, to receive a first airflow from a first exhaust source comprising a first engine, the first airflow having a first mechanical vector and a first temperature, wherein the first exhaust conduit terminates in a mixing chamber;
a second exhaust inlet extending along a second direction, to receive a second airflow from a second exhaust source comprising a second engine, the second airflow having a second mechanical vector and a second temperature, wherein the second exhaust conduit is disposed in the first airflow within the first exhaust inlet, the second direction is perpendicular to the first direction of the first exhaust conduit, and the second exhaust conduit is defined by an elliptical cylindrical enclosure, with a plurality of integrator ports formed through the enclosure;
a first stage comprising an airflow integrator to integrate the first airflow with the second airflow into a first-stage airflow having a third temperature between the first temperature and the second temperature, the airflow integrator comprising a plurality of angled chutes disposed to direct the second airflow from the plurality of integrator ports into the mixing chamber to form a mixed airflow comprising the first and second airflows, the angled chutes being oblique relative to the first direction of the first exhaust conduit; and
a second stage, wherein the first-stage airflow is mixed with air from a first cool air source, the first cool air source having a fourth temperature lower than the third temperature, to provide a second-stage airflow having a fifth temperature between the third temperature and the fourth temperature.

19. The multi-stage exhaust cooling system of claim 18 , further comprising a third stage, wherein the second-stage airflow is mixed with air from a second cool air source, the second cool air source having a sixth temperature, to provide a third-stage airflow havi

Assignees

• Bell Textron Inc
• Gen Electric
• Textron Innovations Inc

Inventors

• Laramee Robert Michael
• Rinehart Michael E
• Steyer William

Classifications

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title

• B64D2033/045

  comprising infrared suppressors · CPC title

• B64D33/04 Primary

  of exhaust outlets or jet pipes · CPC title

• B64C27/04

  Helicopters · CPC title

• F02K1/825 Primary

  Infrared radiation suppressors · CPC title